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  • 1
    Electronic Resource
    Electronic Resource
    Mapping of nutrient-induced biochemical changes in living algal cells using synchrotron infrared microspectroscopy (2005)
    Oxford, UK : Blackwell Publishing Ltd
    FEMS microbiology letters 249 (2005), S. 0 
    Details
    ISSN: 1574-6968
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: High quality Fourier transform infrared (FTIR) spectra were acquired from living Micrasterias hardyi cells maintained in an IR transparent flow-through cell using a FTIR microscope coupled to a synchrotron light source. Spectral maps of living, nutrient-replete cells showed band intensities consistent with the known location of the nucleus and the chloroplasts. These were very similar to maps acquired from fixed, air-dried cells. Bands due to lipids were lowest in absorbance in the region of the nucleus and highest in the chloroplast region and this trend was reversed for the absorbance of bands attributed to protein. Spectra acquired in 10 μm steps across living phosphorus-starved (P-starved) cells, repeated approximately every 30 min, were consistent over time, and bands correlated well with the known position of the nucleus and the observed chloroplasts, corroborating the observations with replete cells. Experiments in which missing nutrients were re-supplied to starved cells showed that cells could be maintained in a functional state in the flow-through cell for up to one day. Nitrogen-starved cells re-supplied with N showed an increase in lipid in all positions measured across the cell over a 23 h period of re-supply, with the largest increases occurring in positions where the chloroplasts were observed. Re-supply of phosphorus to P-starved cells produced no changes in bands attributable to lipid or protein. Due to their thin cell body (?12 μm) and large diameter (?300 μm) Micrasterias sp. make an ideal spectroscopic model to study nutrient kinetics in algal cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/j.femsle.2005.06.021
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    FTIR microspectroscopic study of cell types and potential confounding variables in screening for cervical malignancies (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biospectroscopy 4 (1998), S. 75-91 
    Details
    ISSN: 1075-4261
    Keywords: FTIR microspectroscopy ; cervical cancer ; leukocytes ; lymphocytes ; erythrocytes ; semen ; mucins ; fibroblasts ; thrombocytes ; bacteria ; nylon ; Candida albicans ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: FTIR microscopy was applied to the analysis of cell types and other variables present in Pap smears to ascertain the limitations of infrared spectroscopy in the diagnosis of cervical cancer and dysplasia. It was found that leukocytes, and in particular lymphocytes, have spectral features in the phophodiester region (1300-900 cm-1) suggestive of what has previously been described as changes indicative of malignancy. Endocervical cells and fibroblasts have similar spectral features to HeLa cells and consequently could also confound diagnosis. The use of ethanol as a fixative and dehydrating agent results in retention of glycogen in cervical cell types and thus minimizes spectral changes in the glycogen region due to sampling technique. Spectra of seminal fluids exhibit strong bands in the phosphodiester/carbohydrate region; however, sperm contamination should be easily detectable by the presence of a distinctive doublet at 981/968 cm-1. Erythrocyte spectra exhibit a reduction in glycogen band intensity, but can be discerned by a relatively low-intensity νs $PO^{-}_{2}$ band. Endocervical mucin spectra exhibit a reduction in glycogen bands and a very pronounced νs $PO^{-}_{2}$ band, which is similar in intensity to the corresponding band in HeLa cells. Thrombocytes have strong bands in the phosphodiester region, but thrombocytes can be discerned from other cell types by the presence of two small broad bands at 980 and 935 cm-1. Candida albicans is characterized by strong bands in the polysaccharide region which could potentially obscure diagnostic bands if C. albicans is present in large numbers. Spectra of bacteria common to the female genital tract, in general, also have strong absorptions in the polysaccharide region; however, bacterial contamination is usually minimal and would not be expected to obscure cervical cell spectra. Nylon threads and bristles from cervical sampling implements produce characteristic IR profiles which allow for easy identification. Given the number of potential confounding variables associated with cervical cytology, a multivariate statistical or neural network analysis would appear to be necessary before the implementation of FTIR technology in clinical laboratories. © 1998 John Wiley & Sons, Inc. Biospectroscopy 4: 75-91, 1998
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    An investigation into FTIR spectroscopy as a biodiagnostic tool for cervical cancer (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biospectroscopy 2 (1996), S. 143-153 
    Details
    ISSN: 1075-4261
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: Fourier-transform infrared (FTIR) microspectroscopy, combined with Principal Component Analysis (PCA), was applied in the study of exfoliated cervical cells from 272 patients. Six spectra were recorded for each patient, and these were visually sorted into two types (type 1 and type 2), based on their profiles. Spectra designated type 1 exhibited a profile characteristic of normal epithelial cells, with intense glycogen bands at 1022 cm-1 and 1150 cm-1, and a pronounced symmetric phosphate stretch at 1078 cm-1. Spectra designated type 2 exhibited features suggestive of dysplastic or malignant transformation, with pronounced symmetric and asymmetric phosphate modes and a reduction in glycogen-band intensity.Of the 272 patients, 68.6% of samples exhibited only type 1 profiles for all six recorded spectra, 29.4% of samples yielded at least one type 2 spectrum in any of the six recorded spectra and 2% of samples were inconclusive. Of the 68.6%, 86% were diagnosed normal by Pap smear with no follow up biopsy ordered, 7% were diagnosed abnormal by biopsy, 5% normal by biopsy and 2% were still inconclusive. For the remaining 29.4% of classified samples, 71% had shown an abnormal Pap result. These 71% were subsequently biopsied, and 87% were confirmed abnormal. The association of type 2 spectra and abnormality was further corroborated by spectra of cultured malignant cells from the HeLa cell line that displayed a profile similar to type 2 spectra in the 1300-950 cm-1 region. PCA decomposition using a reduced data matrix resulted in a score plot that showed general separation of the visually categorised spectra. This study demonstrates the potential of automated FTIR cervical screening technology in the clinical environment. © 1996 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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